Several trends presently exist in the semiconductor and electronics industry. One of these trends is that recent generations of portable electronic devices are using more memory than previous generations. This increase in memory allows these new devices to store more data, such as music or images, and also provides the devices with more computational power and speed.
One type of memory device includes an array of resistive memory cells, where individual bits of data can be stored in the individual resistive memory cells of the array. In each resistive memory cell, a layer of programmable material is positioned between two electrodes (i.e., an anode and a cathode). Depending on how the layer of programmable material is biased, it can be put into a more resistive state or a less resistive state. In real world-implementations, the more resistive state can be associated with a logical “1” and the less resistive state can be associated with a logical “0”, or vice versa. Additional resistive states could also be defined to implement a multi-bit cell with more than two states per cell. Perovskite memory, binary oxides random access memory (OxRAM), phase change random access memory (PCRAM), and conductive bridging random access memory (CBRAM) are some examples of types of resistive memory.
In resistive memories, the programmable material may tend to transition from the more resistive state to a less resistive state (or vice versa) over time, depending on which state is more energetically favorable. Due to this drift, data within individual cells may be lost or corrupted, causing data failures. Therefore, methods and devices are needed to reduce this drift. In addition, methods and systems are needed to optimize other memory features, such as access time.